Electrical plug device



b t. 17, 1935. 1 P. CLARK. 4.1R

ELECTRICAL PLUG DEVICE Filed NOV. 5, 1952 Patented Sept. 127;,

UNlTEo STATES PATENT OFFICE ELECTRICAL PLUG nevica Y www: r. clark, Jr., Fairneld, com. application' innemen` 5, 1032, serial N0. 641,401

' comms. (c1. 113-361) The present invention relates to improvements in electrical plug devices, and has for an object to provide in such a device a prong unit which 'may be assembled with great facility and I will be securely held in the insulating housing 'against displacement and distortion, and further '15 cured and tight contact relation with the prong unit, through insertion of the prong unit into With'the above andother objects in view, em`

bodiments of the invention are shown in the 20 accompanying drawing and these embodiments will be hereinafter more fully described with 'reference thereto, and the invention will be finally pointedr out in the claims. In the drawing: 25 Fig.. 1 is a side elevation of an electrical plug device, embodying the invention.

Fig. 2-is a vertical sectional view thereof. i Fig. 3vis a vertical sectional view, taken along the line3-3of Fig. 2. 80 Fig. 4 is a plan view ofthe insulating housing employed.

Fig. 5 is a perspective view of one-of the prong units employed. v y

Hg. 6 is a fragmentary perspective view of the 35 wire attaching end of aY moded form of prong unit. Y

FigJ'l is a fragmentary perspective view of the wire attaching end of a further modified form ofv V prong imit.

Fig. 8 is a side elevati ,partially broken away, of a modiiied form of electric plug device embodyingtheinvention. y

Fig. 9- is a vertical sectional view taken along the line 9-9 of Fig. 8.

45' mg. 10 1s a plan view thereor, partially broken awa Y Fiyg. 11 is an elevation-of the inner side of one of the halves of the insulating'housingemployed l 50 in the embodiment shown in the Figs. 8 to 10.

Fig. 12 is a perspective view of the prong contact unit similar to that employed in the'l embodiment shown in Figs. 8 to 11, but modied by theV inclusion of grooves.

Ilmlisatragmentaryelentlonolthewire attaching end of a further modiiied form of prong uni Fig.'14 is a vertical sectional view taken along the line |4|I of Fig. 13.

Fig. l5 is a Asectional view of a portion of the 5 insulating housing showing .the prong unit illustrated inFigures 13 and 14 inserted therein.

Similar reference characters indicate corresponding parts throughout the several figures of the drawing. 10

Referring to the drawing, the insulating housing or shell I of the plug device, according to the embodiment of the invention illustrated in Figs.

1 to 4, is preferably molded from hard rubber,

Bakelite, or other. suitable material, and is l provided in its upper end with a cylindrical recess II surrounded by an upstanding cylindrical wall I2, a central lead wire passage I3, preferably elongated in cross section, extending from the recess to the lower end of the housing, the lower end of the passage being shouldered, as at Il.

'I'he housing'is provided at each side of the lead wire opening with vertically disposed pockets lS-IS, of rectangular-cross section, for receiving the prong units, beveled at their upper ends,

as at I6, to facilitate insertion of the prong units, and lprovided in their opposed side walls with vertically disposed grooves l1. The end walls of theppckets converge slightly toward their low- -er endsjfor the purpose of binding and securing the prong and lead wire ends inserted therein, and as will hereinafter more fully appear. Pillar posts l8-l8 are found at diametrically opposed points in the recess Il at each end of the passage I3 for mounting a closure plate I9, 35

` threaded holes 20 being provided therein `for receiving the retaining screws 2|-2I inserted through holes 22--22 in the plate.

A pair of prong units 23-23 are secured in the insulating housing, these being in the form 'of elongated metal vstrips of rectangular crosssection to iit into the pockets l5-I 5, the plugging end being of the usual form, beveled, as at 24, and provided with a contacter engaging aperture 25. A boss 26 is pressed in the prong at one side 45 and in the insertedrelation in the socket, as. shown` in Figs. 2 and 3, is adapted to have its upper edge engaged by the closure plate I8. The lower edge presses upon and cooperates in retaining the lead wire ends, as will presently more fully appear. At the lower end of the prong unit there is provided a notch 21, preferably slightly converging toward its closed end and having a widened entrance portion 28 at its lower end tofacilitatepheingoftbeleadwireendthereln.

In operation the lead wire-ends 29- 29 of the cable 30, which is inserted through the passage I3, are placedin the notches 21 ofA theprong units which are lthen pressed into the pockets |5-l5, through the open ends thereof, the wire ends being disposed in the grooves I1 at each side of the pockets and being tightly wedged and pressed therein against the sides of the prong units. At the same time the slight taper of the end walls of the pockets compresses the v'end of the prong unit thus binding the-notch upon the wire and at the same time rmly holds the prong unit in place. The lower edges of the lugs 26 press the wire against the upper end ofthe socket wall and hold them against shifting and displacement. The closure plate I9, which has slots 3| formed therein for engaging-the prong units, is secured in place by the screws 2l and through engagement with the upper edges ofthe lugs 26 retains the units against vertical displacement. The wire ends are thus effectually retained i`n tight electrical contact with the prong units by a snubbing action which prevents their displacement even under very great pulling strains. l

In Figs. 6 and 7 I have shown modied forms of plug units in which the means for engaging the wire end consists of an aperture 32 in the embodiment shown in Fig. 6; and, in the form shown in Fig. 7, of an upwardly inclined tapered notch 33 extending upwardly from one of the vertical edges.

In Figs. 8 to 11 I have illustrated a modified plug device of the type in which an extension plug device may be inserted. The insulating housing, which is of generally cylindrical form, comprises two hollow half-sections 34 and 35, divided in a Vertical plane, and secured together by a. transverse bolt 36 extended through shouldered passages 31 and 38 provided in abutting pillar post portions 39 and 48 of the respective sections. The inner faces of the half sections have recesses and channels therein, which upon joining the sections together form pockets and passages for receiving and retaining the prong land resilient contact units and the lead wires.

The two halves are provided at their upper ends with recesses 4I-4I which when the halves are bolted together form slots through which the plugging ends of the prong and contact units project, and are provided at their lower ends with recesses 42-42 in vertical alignment with the recesses lll-4|, and which in the bolted together relation form slots for the insertion of the plugging ends of another plug device.

A pair-of prong and contact devices or units are secured in the insulating housing, and each is preferably formed by bending a strip of suitable metal upon itself, as at 43, to form a `double thickness substantially rigid plugging portion 44, the two legs being bowed outwardly at-the base of the double thickness portion,l as at 45 and 46, and extended in converging relation to form contactportions 41 and 48. 'I'he bowed portions 45 and 46 provide spring ends for the contact portion 41 and 48, so that they may be sprung apart into parallel prong contacting relation without -vbending between'- their ends, the spring action taking place in the bowed portions. The ends of the contact portions 41 and 48 are iiared outwardly, as at 49 -and 50, to provide prong guidwhich areadapted tosnap into the h ole 5| of a similar prong unit when the latter is plugged into the device.

The double thickness plugging portion 44 is provided in spaced relation above the bowed por- 5 tions'45 and 46 with an.inwardly tapered transversely disposed notch 54 extending from one vertical edge to a point substantially midway between the two vertical edges, and into which the lead wire end is adapted to be engaged, as will presently more fully appear.-

The insulating housing portion 34 is provided near the upper'end with a pair of block portions 55-55 projecting above the inner face of said portion 34 and provided with slots 56-56 in line with the recesses 4| 4l, and into which the prong units are adapted to be engaged. The inner walls of these' portions 55-55 are in paraln lel and spaced relation to a central vertically arranged web 51 extending from the upper end of the housing to the pillar post portion 39, this web being provided adjacent said pillar portion with a cut-out 58, the upper edge of which is-near the lower ends of the block portions 55-55.Vr The web 51 is furthermore provided adjacent the wall of the housing and near the upper end withI an opening 59 adjacent and centrally disposed with relation to a lead wire opening 60 in the housing.

The slots 56-56 of the block portions 55--55 30 are beveled at their upper ends, as at 6l-6l, to facilitate engagement 'of the prong units and provided in their opposed side walls with transverse disposed grooves 62-62. i

The insulating 'housing portion 35 is substantially similar to the portion 34, but instead of the slotted block portions 55-55 is provided with.: a pair of projecting ribs or nger portions 63--63, vbeveled near their outer ends, as at 64-64 and adapted in the bolted relation of the half-sections 40 to engage the sides of the prong units to retain them rmly in the slots 56-56. The portion 35 is provided with avweb '65 similar to the Aweb 51 of the portion 34 and having a cut-out orrecess 66, which with the cut-out 58 forms an interior lead wire opening. A

The two housing portions 34 and 35 are provided with reinforcing webs 68 extending from the pillar posts 39 and 40 to the base and with reinforcing web s 69-69 extending from the pillar posts to the side walls, these latter webs having cut-outs 10-18 for receiving the prong units. 'Ihe bases of the housing portions 34 and 35 are provided with abutment walls 1|-l1l registering with the ends of the slots 427-42 and which in 55 the bolted relation of said housing portions, position the contact ends of the prong and contact units.

In operation, the lead wire ends 12-12 of the cable 13, which is inserted through the opening 60 are carried through the opening 58 at each side of the web 51 and thence in criss-cross relation through the opening 59 into relation with respective prong units, the exposed ends of the wires being placed in the notches 54-54 and the prong units then pressed inthe slots 56-56 through their open ends, the wire ends being disposed in the grooves G2-62 at each side of the pockets and being tightly wedged and pressed therein against the sides of the prong units. The housing nportion 35 is then bolted in place, the

iitiil i sillllb :presagi a )um i la mii cli dloidlln si l un q n prin u; 1 l1 linkin il itl le: clxsahtei a [aint tulib nailed :eh sintesi rtl4 i l f 1 enagfinn El :In delle: ,dv ins: a tp rsdnsiitin maint :taining c in tight electrical contact with the prong units by a snubbing action which prevents their displacement even under great pulling strains.

In Figs. 13 to 15 I have illustrated a further modiication in which a prong unit 23", substantially similar to the unit 23 shown in Figs. 1 to 5,'

l is provided at each side and between the notch 21* and the boss 26" with grooves 14-14 which may be pressed, milled, or otherwise formed therein, and in which the wire ends are adapted to engage, in the inserted relation in the socket I5a of the -insulating housing I0, as shown in Fig, 15. In

this form the socket is provided with at sides, the grooves as provided in the iirst embodiment being dispensed with.

Obviously the other embodiments may be sim- Having thus described my' invention, what Iv claim and desire to secure by Letters Patent isz- 1. In an electrical plug device, a housing of insulating material having a prong receiving pocket portion comprising a pair of Aopposed spaced side surfaces and an open end, and a metallic prong unit comprising a wire attaching portion disposed in said pocket portion and a.

plugging portion projecting therefrom, said wire attaching portion being engageable with said pocket portion through said open end and by movement parallel tothe axis of said pocket portion which axis is perpendicular to said open end, said wireattaching portion having an open-ended notch extending inwardly from one surface, the wire attached to said prong unit projecting from said open end of said pocket portion and having a U-shaped end portion embracing said wire attaching portionl with its bight disposed in said notch and 'its side legs disposed at each side of 10 saidwire attaching portion and extending from said bight toward said open end of said pocket portion, said side legs being pressed between the side surfaces of said wire attaching portion and the side surfaces of said pocket portion, the side 15 surfaces of one of said portions each having a groove for receiving and positioning a side leg of said wire. said grooves being parallel to said axis of said pocket portion.

' 2."In an electrical plug device, a housing of 20 insulating material having a prong receiving portion, said receiving portion comprising side walls and end Walls, said end walls converging toward their lower ends and a metallic prong unit engaged in said receiving portion and having a bi- 25 furcated wire receiving portion adapted to position a wire end at each side of said prong, said wire end portions at each side of said prong being held-between the sides of said prongunit and said side walls of said prong receiving por- 30 tion through engagement of said prong um't therein, and said prong being transversely compressed by said converging end walls of the prong receiving portion.

LANCASTER P. CLARK, JR. 

